MCALLEN — Every afternoon, dozens of immigrant families released by the U.S. government walk three blocks from the Greyhound bus station in this South Texas border city to a migrant shelter run by Catholic Charities.

LAS CRUCES, N.M. — Groups advocating for the rights of children and families detained at the southern border are using the Freedom of Information Act to find out exactly where the Trump administration plans to build migrant detention centers on two military bases in the Southwest.